The present invention relates to a physiotherapeutic device and more particularly but not exclusively to devices for providing both electrotherapeutic and thermotherapeutic treatment in combination.
The use of heat and cold for therapeutic purposes is well known. Hot water bags, ice packs, and the like have commonly been used to alleviate pain, to stimulate the flow of blood, or to restrict the flow of blood beneath the surface of the skin. One of the problems with hot water bags is that the temperature steadily decreases during use, thereby necessitating refilling them with a heated liquid. Ice packs steadily increase in temperature when applied to the skin, and ice must accordingly be added from time to time if a cold temperature is to be maintained. It is also difficult to regulate the temperature of an ice pack or a hot water bottle such that it is neither too cold nor too hot when applied to the skin.
A number of therapeutic devices have been developed which employ Peltier thermoelectric units for providing heat or cold. Such devices include switches which allow reversing the polarity of the current passing through the thermoelectric units, thereby determining whether a hot or a cold stimulus is to be applied thereby. U.S. Pat. No. 3,207,159 discloses such a device which includes a probe for heating or cooling selected cutaneous points. U.S. Pat. Nos. 4,585,002 and 4,860,748 disclose devices which employ microprocessors for controlling the duration and/or intensity of heat and cold generated by Peltier thermoelectric units. U.S. Pat. Nos. 3,133,539, 3,168,895, 4,640,284 and 4,915,108 disclose various other therapeutic devices for applying heat or cold to the skin.
Therapeutic electrical stimulation of soft body tissue is well known. These devices which produce transcutaneous electrical nerve stimulation are known as TENS devices and are used to both relieve chronic pain and to produce muscle building stimulation.
As mentioned above, it is also well known to treat injured and weakened soft body tissue through the use of the topical application of heating atop the body tissue to be treated.
Specifically, devices beginning with the earliest of the resistive wire heating pads are well known in the art to accomplish the individual function of heating. The more recently developed TENS units are well known for therapeutic electrical stimulation of muscles and soft body tissue. A more complex therapeutic device for providing either one of heating and cooling of the skin and underlying body tissue is disclosed in U.S. Pat. No. 5,097,828 invented by Deutsch. This device includes a handle and a thermally conductive head which utilizes Peltier effect devices for heating or cooling a contact plate within the head. The contact plate may also be connected to a high-voltage source for electrical stimulation.
In U.S. Pat. No. 5,336,255, Kanare et al. have disclosed an electrical stimulation and heating or cooling pack which includes a nonconductive pouch and straps for positioning and holding the pouch against a body part. Flexible conductive patches attached to the pouch are connectable to a remote pulse generator. An electrically conductive adhesive gel pad is also provided for coupling the conductive patch to the body part. By this arrangement, both heating or cooling and electrical stimulation of a body part are provided.
U.S. Pat. No. 5,601,618 discloses a very simple device for providing combination electrical stimulation or TENS-type soft body tissue stimulation and the simultaneous heating of the body tissue. The device is hermetically sealed and extremely compact and portable, relying upon low current dry battery power for heating and the utilization of double-sided adhesive conductive electrodes which adhesively attach to the skin area over the soft body tissue for supporting the device against the skin during use.
A combination soft body tissue stimulator and heating device includes a thin, flat, molded flexible plastic pad, one side of which defines a working surface. The molded pad has a plurality or an array of spaced separate conductive areas each having an exposed conductive surface, being generally coplanar with the working surface. When the device is properly installed, each conductive area makes electrical contact with, and receives support from, a separate disposable double-sided flexible adhesive electrode attached to the skin over the soft tissue. The array of electrodes adhesively attached to the skin is generally aligned with the array of conductive areas of the pad so that only the adhesive attachment between the conductive areas and the electrodes is required to hold the device in place against the skin. A resistive heating element is embedded within the pad, which pad is generally coextensive with and electrically isolated from the array of conductive areas on the side thereof away from the working surface. The conductive areas are connectable to a pulsed electrical current and the heating element is connectable to a D.C. battery supply for simultaneous stimulation and heating of any desired soft body tissue area.
A particular use for treatments of this type is in relation to post-surgical trauma and trauma resulting from, for example, sports-related injuries, this being a common occurrence with which patients must regularly contend. The trauma often manifests itself in the form of swelling which results from the accumulation of bodily fluids underlying the skin adjacent to the site of the trauma. Such swelling not only results in patient discomfort, but also inhibits recovery, as it results in an increased application of pressure against the tissue and surrounding nerve and organ structures. Furthermore, such swelling reduces patient mobility when the trauma is of an orthopedic nature. For all of the foregoing reasons, it is a common objective of health care professionals to reduce the accumulation of undesired fluid underlying the site of patient trauma as soon as possible. To date, such fluid reducing measures have typically encompassed the application of cold compresses such as ice packs for prescribed periods of time to the site of the trauma, followed by the application of hot compresses.
As discussed above, non-powered cooling solutions such as cold compresses are oftentimes initially too cold for the patient to comfortably tolerate and, as a result, the patient is unable to tolerate the cooling effects of the compresses for the prescribed period of time. Furthermore, because the compresses remove heat from the body, the temperature of the compresses themselves progressively increases, thereby diminishing their temperature reducing affects. Longer periods of cooling can be provided by increasing the amount of coolant such as ice in the cold compress; however, such practices increase the size of the compress, thereby adversely impacting upon the compresses"" ability to conform to the site of the trauma and compromising their effectiveness in removing heat from the site of the injury.
An optimal regimen for reducing tissue swelling provides for treatment with cold compresses for up to about 72 hours followed by warm compress treatment for a period of about 10-14 days. Furthermore, because water has a high specific gravity, the provision of additional quantities of ice in the cold compress further increases the downward pressure exerted against the trauma site, thereby negating to some extent the benefits afforded by cold compress treatment. Further problems arise as a result of the considerable time demands of personnel at health care facilities, as the cold and hot compresses used in such facilities often times cannot be properly monitored and changed prior to loss of their effectiveness, particularly during overnight and prolonged stays.
As a result of all of the foregoing deficiencies in the prior art, patient recovery from physical trauma surgery and inflammation is often prolonged, resulting in increased patient discomfort, lack of motility in instances of orthopedic trauma, and prolonged periods of patient medication resulting from discomfort arising from the trauma and the prolonged presence of subcutaneous swelling.
As discussed above, patient recovery from trauma can be expedited by the application of transcutaneous electrical neurostimulation (TENS), which typically involves the application of an alternating current (AC) potential to the tissue by way of two or more electrodes of opposite polarity
U.S. Pat. No. 5,169,384 to Bosniak et al, discloses a temperature variable and iontophoretic device for application to the body of a patient, which has an outer support member coupled to a device for selectively applying thermal energy to the body of a patient or for removing thermal energy therefrom, and a further device for selectively energizing the thermal energy supply and removal device. Another member is coupled to the outer support member for iontophoretically administering a compound to the body of the patient. The energizing device comprises a user-operable data input device, which also controls the iontophoretic administering device. Transcutaneous electrical neurostimulation (TENS) can also be provided.
Heat or cooling based treatment is particularly effective at reducing pain, as discussed above, but advantageous levels of heating or cooling may easily cause burns if the heat source is not removed within an appropriate amount of time. The appropriate amount of time varies depending on the temperature deemed necessary in the treatment and thus renders the type of treatment unsuitable for unsupervised use by a patient. Both unpowered and powered treatment devices have to be removed from the treatment site before a burn appears.
Furthermore, the above combination devices, that provide both thermal and electrical treatment, do not apply point electrical stimulation to a point within the area of the thermal stimulation because the heat pad cannot serves as both of the two required electrodes.
It is an aim of the present invention to provide a treatment device that is simple and safe to use unsupervised by a patient in view of all of the aforementioned problems and which can provide localized electrical and thermal stimulation together to a small localized region.
According to a first aspect of the present invention there is thus provided a physiotherapeutic device for concurrently providing heat transfer and electrical stimulation to a localized treatment area, the device comprising:
a heat transfer medium for placing in contact with said treatment area, said heat transfer medium comprising a thermo-conductive material and having a heat capacity such that said device is operable to change a temperature gradient within of said heat transfer medium from one able to induce a burn to a safe temperature substantially within a minute,
at least one electrode located within said heat transfer medium, said electrode comprising a thermo-conductive material, and
a dielectric layer for providing electrical isolation between said electrodes and said heat transfer medium, said dielectric layer comprising a thermo-conductive material. Preferably the heat transfer is bi-directional although embodiments are envisaged which are solely for heating or solely for cooling.
Preferably, the heat transfer medium has an external dielectric covering.
Preferably, the electrodes are thermally coupled to said heat transfer medium via said dielectric layer.
A preferred embodiment has a temperature range of at least 40 degrees between a maximum treatment temperature and a minimum treatment temperature, and being operable to permit said heat transfer medium to alternate between said maximum and said minimum treatment temperatures in substantially one minute.
A preferred embodiment has a plurality of electrodes integrally located within said heat transfer medium.
In a preferred embodiment, each electrode is programmable independently to provide electrical stimulation.
Preferably, said electrodes and said heat transfer medium are programmable separately to provide a combined regime of electrical and heat treatment.
Preferably, the electrodes are programmable to provide electrical stimulation selectably as a constant voltage level, a constant current level, and a selectable waveform at a selectable frequency.
Preferably, the device is programmable remotely over an electronic network.
Preferably, the electrode has a thermal diffusivity substantially similar to a thermal diffusivity of said heat transfer medium.
According to a second aspect of the present invention there is provided a physiotherapeutic device for concurrently applying heat, cooling, and electrical stimulation to a localized treatment area, the device comprising a heat transfer medium for placing in contact with said treatment area and at least two electrodes integrally located within said heat transfer medium and electrically insulated therefrom.
A device according to the invention preferably has a dielectric layer intervening between at least one electrode and said heat transfer medium.
Preferably, the device has a temperature range of at least 40 degrees between a maximum treatment temperature and a minimum treatment temperature, and having a combination of heat control power, heat transfer medium size and heat transfer medium thermal diffusivity selected to permit said heat transfer medium to alternate between said maximum and said minimum treatment temperatures in substantially one minute.
Preferably, the device has a plurality of electrodes, each electrode being programmable independently to provide electrical stimulation.
Preferably, the electrodes and said heat transfer medium are programmable separately to provide a combined regime of electrical and heat treatment.
Preferably, the electrodes are programmable to provide electrical stimulation selectably as a constant voltage level, a constant current level, and a selectable waveform at a selectable frequency.
Embodiments are preferably programmable remotely over an electronic network.
Preferably, the electrodes are thermally coupled to said heat transfer medium.
Preferably, the dielectric layer is a heat conducting layer.
Preferably, the heat conducting medium has an outer dielectric coating.
Preferably, the dielectric layer is a heat conducting layer.
According to a third aspect of the present invention there is provided a method of manufacturing a physiotherapeutic device, comprising the steps of
providing a heat transfer medium having a low heat capacity,
providing openings in said heat transfer medium,
lining said openings with a dielectric material, and
inserting electrodes through said lined openings.
Preferably, the dielectric material comprises a thermal conductor.
Preferably, the thermal conductor comprises aluminum oxide.
In an embodiment, the gaps are arranged circumferentially in said surface.
Typically the gaps may be arranged as segments in said surface.
Alternatively, the gaps may be arranged circumferentially around said surface.
As a further alternative, said gaps may be arranged successively outwardly radially around a center of said surface.
A preferred range for the separation between electrodes is between 5 and 50 mm.
According to a fourth aspect of the present invention there is provided a method of providing combined electrical and thermal stimulation to a treatment area, the method comprising the steps of:
applying to said treatment area an integral electrode and heat transfer medium comprising a plurality of electrodes arranged within a heat transfer medium, thermally coupled thereto and electrically insulated from one another,
applying electrical stimulation via said electrodes, and
applying thermal stimulation via said integral electrode and heat transfer medium.
Preferably, the thermal stimulation comprises changing a temperature of said surface by substantially 40 Celsius within substantially one minute.
The method preferably comprises providing changing voltages at at least one of said electrodes.
The method preferably comprises providing changing currents at at least one of said electrodes.
The method may also comprise providing independent waveforms to at least two of said electrodes.
Alternatively or additionally the method may comprise providing cyclical changes in a direction of thermal transfer over a treatment time.
Alternatively or additionally, the method comprises providing irregular cyclical changes over a treatment time.
Preferably, the method comprises applying said treatment to a plurality of treatment regions by using a plurality of integral electrode and heat transfer media, each applied to a different one of said plurality of treatment regions.